New weta species discovered on threatened plateau in New Zealand

The weta has been informally named the “Denniston white-faced weta” for its distinctive white markings behind its head.

November 2012. A new species of cave weta has been discovered on the West Coast's Denniston Plateau, which, if an Australian mining company has its way, will also be the site of a 190ha open-cast coal mine. The weta has been informally named the "Denniston white-faced weta" for its distinctive white markings behind its head. It was discovered on the plateau by Massey University evolutionist Steve Trewick, who was immediately struck by the weta's unusual appearance.

Trewick said "It just stood out. We haven't seen anything with that appearance and colouration. Males and females are almost black with an unusual, prominent white marking behind their head."

Members of Massey University's ‘Phoenix' evolution, ecology and genetics group, led by associate professors Steve Trewick and Mary Morgan-Richards have been researching and classifying the weta.

Distinctive DNA sequence, the combination of spines on the legs and the shape of the females' subgenital plate all indicate this is a species new to science. But Steve Trewick says more work needs to be done to determine the genus and whether it is endemic to the Denniston Plateau.

"This weta might occur elsewhere as well as Denniston, but what it highlights is that destroying distinctive habitat is likely to destroy biodiversity even before we know it is there. If we're destroying biodiversity before we've even identified it, we're clearly following the wrong strategy," he says.

Unique geological composition
The plateau's unique geological composition in combination with atypical weather conditions, including an annual rainfall of 6m, has created ecosystems that support wildlife found nowhere else in the world.

Forest & Bird's Top of the South Field Officer Debs Martin says the discovery illustrates the rich ecological tapestry of the plateau and underscores why the plateau must not be mined.

"This new weta highlights the fact that the plateau is an incredibly diverse place that we don't know a lot about. Laying waste to such a unique area of New Zealand that's protected as conservation land would be a travesty," she says.

New moth
A new species of day-flying moth, the Avatar Moth, was also discovered on the plateau earlier this year.